Khan.scratchpad.disable(); To move up to the maestro level in his piano school, Kevin needs to master at least $191$ songs. Kevin has already mastered $9$ songs. If Kevin can master $10$ songs per month, what is the minimum number of months it will take him to move to the maestro level?
To solve this, let's set up an expression to show how many songs Kevin will have mastered after each month. Number of songs mastered $=$ $ $ Months at school $\times$ Songs mastered per month $+$ Songs already mastered Since Kevin Needs to have at least $191$ songs mastered to move to maestro level, we can set up an inequality to find the number of months needed. Number of songs mastered $\geq 191$ Months at school $\times$ Songs mastered per month $ +$ Songs already mastered $\geq 191$ We are solving for the months spent at school, so let the number of months be represented by the variable $x$ We can now plug in: $x \cdot 10 + 9 \geq 191$ $ x \cdot 10 \geq 191 - 9 $ $ x \cdot 10 \geq 182 $ $x \geq \dfrac{182}{10} \approx 18.20$ Since we only care about whole months that Kevin has spent working, we round $18.20$ up to $19$ Kevin must work for at least 19 months.